Rear turnsignal lens problem..cracking

the Ferret · Apr 3, 2014

2006 ST 1300. I bought it new. 38,000 miles. always garage kept, never backed into anything, never been rear ended, never been on the ground, not even in a parking lot ie no tip overs, other than on trips never really been in the rain. Both turn signals lenses where they meet the tail light lens, spider webbing cracking.Does anyone else have this problem? Is it common? What could possibly be causing it?

left

right

rear

SupraSabre · Apr 3, 2014

With all three bikes, and over 200K between them, I never saw anything like that!

Byron · Apr 3, 2014

It could have something to do with the local environment, extreme cold.

Highrider · Apr 3, 2014

Those lenses are made from polycarbonate that can craze and crack if exposed to oils or chlorinated compounds. The cracks are in the area that the sections were sonic welded together, those areas could have a lot of stress from the welding.
Have you ever had the rear light / fender apart for wiring in the rear?

Culomorena78 · Apr 4, 2014

I have a spare tail light assembly. I need to inspect it to see if it has any cracks. let me know if you would have any interest in picking it up for a nominal fee. email me at edwardwilliamturner@yahoo.com

970mike · Apr 4, 2014

I have not seen any others that have done that.

SteveST1300 · Apr 4, 2014

130K on mine no similar problems and never seen another like that.

Scooter · Apr 4, 2014

Highrider said:
Those lenses are made from polycarbonate that can craze and crack if exposed to oils or chlorinated compounds. The cracks are in the area that the sections were sonic welded together, those areas could have a lot of stress from the welding.

This was my first thought also. Also wondering if an impact to the nose of the taillight might have propagated the force to those areas. Mine doesn't show any of those cracks and I've never seen anybody else on the forum complain about them until now...

the Ferret · Apr 4, 2014

It's definitely weird. I thought maybe I overloaded the trunk or bags or something on one of the trips. There has never been an impact to the nose of the taillight that I am aware of. There have never been any harsh chemicals used on it. S100, water and Honda spray polish, that's it. Definitely perplexing.

the Ferret · Apr 4, 2014

Highrider said:
Those lenses are made from polycarbonate that can craze and crack if exposed to oils or chlorinated compounds. The cracks are in the area that the sections were sonic welded together, those areas could have a lot of stress from the welding.
Have you ever had the rear light / fender apart for wiring in the rear?

Nope never been apart. I have a trunk, but it's not wired in.

dohboy · Apr 4, 2014

Mickey, have you ever slept near your ST? It might be from the decibel level and vibrations caused by you when you sleep. It's the only thing that's different then the others.

the Ferret · Apr 4, 2014

dohboy said:
Mickey, have you ever slept near your ST? It might be from the decibel level and vibrations caused by you when you sleep. It's the only thing that's different then the others.

Lol..dang that is going to follow me everywhere from now on. No wonder every one says " No..our cabin is full " whenever I inquire.

BakerBoy · Apr 4, 2014

Sonic welding isn't stress free and it should have been annealed to relieve the stresses. It appears that cracks in the joint also have spread out from the joints into the surrounding red and amber lenses, cracking perpendicular to the joint.

I doubt you could have affected the outcome.

First time I've heard of one here.

the Ferret · Apr 4, 2014

Well, regardless of cause, I think Culomorena78 (Mr. Turner) is going to fix me up and the back end of my ST will be back to pristine in the not too distant future. Thank you sir!

Culomorena78 · Apr 4, 2014

My pleasure. I purchased it originally with the intention of coming up with a way to make bright led lights work. I got as far as looking at it. Hope it helps you out and isn't too much of a bear to replace.

the Ferret · Apr 5, 2014

Looks like there are only 2 bolts holding it on from your pictures. Now where those bolts are is a mystery at this point lol.

970mike · Apr 5, 2014

You will see how to change it out once you get in there. It is not to bad to pull it out.

st1300r · Apr 5, 2014

Mine has had it for years. Doesn't leak so I don't worry about it. Not as bad as yours tho.
As mentioned polycarb is prone to stress cracking. Could be the cleaner you use, molded in stress when it was made, from the assembly process or uv. Don't know if it's molded as one pc or joined afterwords never looked that close.
(you can mold different colors with a 2 or even 3 shot machine) Unless there's a specific reason most buyers aren't going to pay to have molded parts annealed.

the Ferret · Apr 5, 2014

Carl, mine has been like that for a couple years as well, but seems to be getting worse lately. I have only used S 100 and water or bike brite ( same thing basically) and water, followed by Honda Spray polish about twice a year since new.

SupraSabre · Apr 9, 2014

Since the inner rear fender is in the way, you'll pull the rack off, along with the rear cowl, which the light is attached to.

http://hamptonrpi.com/V4Files/Transplant%202004-to-2010/images/dsc00455.jpg

http://hamptonrpi.com/V4Files/Transplant%202004-to-2010/images/dsc00456.jpg

http://hamptonrpi.com/V4Files/Transplant%202004-to-2010/images/dsc00459.jpg

http://hamptonrpi.com/V4Files/Transplant%202004-to-2010/images/dsc00468.jpg

Sorry the pictures of the rear cowls aren't clearer...and I don't have any of the underside...I think there are three bolts that connect the rear cowl with the taillight.

Rear turnsignal lens problem..cracking

the Ferret

Daily rider since May 1965

SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired

Byron

Highrider

Part time mechanic

Culomorena78

970mike

Mike Brown

SteveST1300

Scooter

This space for rent...

the Ferret

Daily rider since May 1965

the Ferret

Daily rider since May 1965

dohboy

the Ferret

Daily rider since May 1965

BakerBoy

It's all small stuff.

the Ferret

Daily rider since May 1965

Culomorena78

the Ferret

Daily rider since May 1965

970mike

Mike Brown

st1300r

the Ferret

Daily rider since May 1965

SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired